 (defn button-bar [world]
   (let [wld @world
         ha-defs (:ha-defs wld)]
-    (sab/html [:div {:style {:position "fixed"}}
+    (sab/html [:div {:style {:position "fixed" :top 0}}
                [:button {:onClick #(swap! world
                                           (fn [w]
                                             (assoc w :playing (not (:playing w)))))}

                  :scroll-y        (:scroll-y world-desc)
                  :camera-width    (:camera-width world-desc)
                  :camera-height   (:camera-height world-desc)
                  :view-width      640
                  :view-height     480
                  :width           (:width world-desc)
                  :height          (:height world-desc)
                  :walls           walls})))

                                                                               ;create new object and set sel to it and enter either moving state (for HAs) or resizing state (for walls)
                                                                               ; multi-selection or HA selected or mouse in center
                                                                               (editor-start-new-thing ed down-x down-y wx wy)
                                                                               (or (> (count sel) 1)
                                                                                   (= :objects (ffirst sel))
                                                                                   (= :live-objects (ffirst sel))
                                                                                   (wall-centerish-point? (get-in (:draft-desc ed) (first sel)) wx wy))
